Catalytic preparation of carboxylic acid esters from olefins, alcohols and carbon monoxide in the presence of an alkyl ether or alkyl ketone promoter

ABSTRACT

A process is described for preparing carboxylic acid esters from olefins, alcohols and carbon monoxide using a combination of tin or germanium salt and a haloplatinum acid as the catalyst and a ketone or ether promoter. Olefins having from eight to about 24 carbon atoms are preferred reactants. Alkyl ketones having up to 11 carbon atoms and alkyl ethers having up to 16 carbon atoms are useful promoters. The reaction rate is unexpectedly improved by the promoter.

United States Patent Schell [54] CATALYTIC PREPARATION OF CARBOXYLIC ACID ESTERS FROM OLEFINS, ALCOHOLS AND CARBON MONOXIDE IN THE PRESENCE OF AN ALKYL ETHER OR ALKYL KETONE PROMOTER [72] Inventor: Raymond A. Schell, Berkley, Mich.

[73] Assignee: Ethyl Corporation, New York, NY.

[22] Filed: March 20, 1970 [21] Appl. No.: 21,472

Related US. Application Data [63] Continuation-impart of Ser. No. 671,110, Sept.

27, 1967, abandoned.

52 us. c1 ..260/4l0.9 R, 260/408, 260/410, 260/4105, 260/468 M, 260/478, 260/479 R,

260/484 R, 260/485 R, 260/486 AC,

51 1m. (:1 ..C07C 67/00 1151 3,681,415 [4 1 Aug. 1,1972

[58] Field ofSearch ..260/410,4l0.9 R497 A, 486 AC, 410. 5, 479 R, 468

Primary Examiner Lewis Gotts Assistant Examiner-Diana G. Rivers Attorney-Donald L. Johnson [5 7] ABSTRACT A process is described for preparing carboxylic acid esters from olefins, alcohols and carbon monoxide using a combination of tin or germanium salt and a haloplatinum acid as the catalyst and a ketone or ether promoter.

Olefins having from eight to about 24 carbon atoms are preferred reactants. Alkyl ketones having up to 1 1 carbon atoms and alkyl ethers having up to 16 carbon atoms are useful promoters.

The reaction rate is unexpectedly improved by the promoter.

33 Claims, No Drawings EATALYITQ PREPTION OF C e il' OXYLIC ACE!) ESTERS FROM OLEFINS, ALCOHOLS CARBON MONOXIDE IN FENCE OF AN ALKYL E r OR ALKYL KETONE PROMOTER CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of Ser. No. 671,110, filed Sept. 27, 1967, now abandoned.

BACKGROUND OF THE INVENTTON This invention is directed to an improved process for preparing carboxyiic acid esters from olefins, carbon monoxide and alcohols.

The reaction of primary alcohols with olefins and carbon monoxide to produce esters is well known. There are a number of U. S. patents describing the use of various catalysts for this reaction, see for example, US. Pat. Nos. 2,542,767, 2,526,742, 2,557,256. An especially useful catalyst system is described in U. S. Pat. No. 2,876,254. The process therein described is directed to the reaction of olefins having up to six carbon atoms with carbon monoxide and an alcohol using as a catalyst a combination of a tin or germanium salt with a Group VH1 metal salt. When higher molecular weight olefins such as dodecene are used in this process, the yield of ester product is low and the rate of reaction is poor.

It has been discovered that the rate of carboxylating higher molecular weight olefins using a catalyst of U. S. Pat. No. 2,876,254 is significantly increased by carrying the reaction out in the presence of ethers and ketones as promoters.

SUMMARY OF THE INVENTION A process for preparing carboxylic acid esters which comprise reacting an olefin having from about two to about 32 carbon atoms with carbon monoxide and an alcohol using a catalyst which is a combination of a salt of tin or germanium with a haloplatinic acid and a promoter selected from alkyl ketones and alkyl ethers.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of this invention is a process for preparing carboxylic acid esters which comprises reacting a C -C olefin characterized by (1) having at least one a-carbon-to-carbon double bond and (2) having a hydrogen on the 2 carbon atom of said a double bond with carbon monoxide and a C -C alcohol in the presence of a catalyst which is a combination of an alcohol soluble salt of a metal selected from the class consisting of tin and germanium with haloplatinic acid and of an alkyl ketone or alkyl ether promoter. A preferred embodiment is the process described above in which the catalyst is a combination of (a) a tin or germanium halide with a haloplatinic acid or (b) a tin or germanium halide with chloroplatinic acid or (c) stannous chloride dihydrate and chloroplatinic acid hexahydrate. C C monohydroxy alkanols are preferred reactant alcohols. Alpha monoolefins are Organic compounds which are useful reactants in the practice of this invention are olefins (it) having at least one alpha carbon-to-carbon double bond and (2) a hydrogen atom on the 2 carbon atom of said a double bond. These olefins include mono unsaturates, that is, compounds having one or carbon-to-carbon double bond as well as polyunsaturates, that is, compounds having two or more carbon-to-carbon double bonds. Useful olefins may contain other functional groups such as hydroxy, halo, carboxy, nitro and the like. Examples of useful unwturated organic compounds are 3 chlorooctene-l, 9-hydroxytetradeeene-l, and the like. Preferred olefins are the hydrocarbon olefins. Examples of preferred olefins are octene-l, pentadecene-l, tetraisobutylene, cyclooctene, cyclooctadiene-l ,5, dodecene-l, eicosene-l, nonene-l, octadecene-l and the like. Most preferred olefins are the acyclic o: olefins. Examples of preferred olefins are tetracosenel, octadecadiene-l,3, undecadiene-l,4, and the like. Especially preferred hydrocarbon olefins are the amonoolefins, that is, hydrocarbons having only one carbon-to-carbon double bond in the 1,2 position in the molecule. Examples of suitable a-monoolefins are ethylene, 4-methylpentene-l, butene-l, 3-methylbutene-l, octene-l, nonene-l, decene-l, tetradecene-l, dodecene-l, S-ethylhexene-l, pentadecene-l, heptadecenel eicosenel and the like.

Commercial mixtures of olefins are also quite useful. These commercial mixtures are generally a mixture of various homologous olefins such as C C C olefins; 5. 1, 9, 11 olefins; 12, 14, C18 olefins; 12, 14 olefins; 13, 15 11 olefins; u 12, 13 14, C161 C18, C C C C C olefms, and the like. These mixed olefins are synthesized for example by the Ziegler catalyzed polymerization of low molecular weight olefins such as ethylene or propylene; or by the dehydrogenation of suitable paraffins. The mixed olefins thus obtained might also contain minor amounts of other nonhomologous olefins and non-olefin components. In any case, the mixed product obtained from such a commercial synthesis need not be separated into the individual components to be useful. Mixtures of even carbon numbered predominantly a olefins in the C C range having an average molecular weight of C -C are useful; C -C range mixtures are particularly useful. Such mixtures containing C to C predominantly a-olefms are especially useful. By predominantly I mean that over 60/o of the olefins are alpha.

Alcohols which are useful reactants include both aryl as well as alkyl hydroxycompounds. Examples of suitable aryl hydroxy compounds are benzyl alcohol, phenol, C to C alkyl phenols, and the like. The preferred alcohols are the alkyl hydroxy compounds having from one to about 10 carbon atoms wherein the alkyl group is composed solely of carbon and hydrogen. The term hydrocarbyl alkanols is used to describe these preferred alcohols. These hydrocarbyl alkanols include cyclic alcohols such as cyclohexanol, cyclopentanol and the like, as well as primary, secondary and tertiary alcohols such as 2-decanol, tert-butanol, 2-ethylhexanolland the like. The most preferred alcohols are the acyclic hydrocarbyl monohydroxy primary alkanols having from one to about five carbon atoms such as ethanol, pentanol-l, butanol and the like. Methanol is an especially preferred alcohol.

The catalysts which are used in efiecting the reaction are in general a combination of alcohol soluble salts of tin or germanium with a haloplatinum acid. Preferred haloplatinum acids are those wherein the halogen has an atomic number of at least 17. The chloroplatinum acids are especially preferred. Specific examples of suitable salts of tin and germanium are stannous and stannic chlorides, bromides and iodides, germanium diand tetrachlorides and germanium tetrabromides, tetraiodides and tetrafluorides, stannous and stannic sulfates and the like and their hydrates. Stannous chloride is preferred either anhydrous or hydrated.

Suitable haloplatinum acids are chloroplatinous acid, bromoplatinic acid, iodoplatinic acid, bromoplatinous acid, and iodoplatinous acid. Chloroplatinic acid is preferred, either anhydrous or hydrated.

An especially useful catalyst combination is SnC1 -2 H and H2},

Special preparation of the catalysts does not appear to be required. In general, as set out in U.S. Pat. No. 2,876,254, the suitable metal salts are dissolved directly in the alcohol reactant which is being used in the carboxylation. Molar ratios of alcohol soluble tin or germanium salt to haloplatinum acid of from 1:1 to 20:1 can be used in the preparation of the catalysts. The amount of catalyst which can be employed can be varied widely, but is generally about 0.0001 to about moderate amounts of water. Thus, for example, the reaction to produce esters will proceed when the catalyst components bear water of hydration (e.g. SnCl -2l-l 0, H

-4.5 H O) or when the alcohol reactant is not anhydrous and the like. Excess amounts of water, that is, over about 1.3 moles of water per mole of olefin reactant, should be avoided.

The temperature at which the reaction is carried out may vary over a wide range. In general, temperatures in excess of about 30 C. are used. The temperature range of from about 30 C. to about 325 C. may be employed. Temperatures from about 50 C. to about 275 C. are conveniently used. Temperatures ranging from about 70 C. to about 120 C. are preferred. The process may be carried out under pressure ranging from 500 to about 10,000 pounds per square inch (p.s.i. Reaction pressures of from about 750 to about 5,000 psi. are conveniently used.

The product obtained in the present carboxylation process is a mixture of ester isomers. This is illustrated by the following reaction equation:

promoter catalyst CHa-(CH:)5CH=CH2 R-0H 00 0 0 l l oH,- cH, l-c11, omb o a omcHnrpH-do H (linear) (branched) bis[ 2( Zb-methoxyethoxy )ethyl ether, bis( 2ethyl)ether,4 5

l,2-dipropoxy propane and the like. Mixtures of the promoter compounds can also be used.

Especially preferred promoters are acetone and 1,2- dimethoxy ethane.

As will be illustrated below these promoters unexpectedly improve the rate of the catalytic carboxylation of C and higher olefins to produce esters.

The amount of promoter used ranges from about 10 percent to about 70 percent by weight of the total alcohol/olefin charge. Generally, 20 percent to about 60 percent by weight of the promoter can be used.

The action of the promoter is not fully understood. Although not bound by any theory, it is thought that the promoter may function as a complexing agent. Whatever the mechanism, the presence of the promoter unexpectedly improves the overall rate of the carboxylation reaction.

Water is not required in the present process. In other words, the reaction to produce esters will proceed with essentially no water present. However, water need not be excluded from the present process; and, in fact, the process can be carried out in the presence of up to The product obtained thus, is a mixture of linear and branched esters. The major product obtained in the present process is the linear ester. By major product I mean more than about 60 percent by weight of the ester mixture is the linear ester.

This mixture of ester isomers may be separated if desired by any suitable separation methods such as by fractional distillation, by selective absorption, and the like. The mixture of esters may likewise be used as such without any separation of isomers.

As the examples which follow will show, by using the promoter, the rate of the carboxylation reaction is increased substantially. In the following examples all parts are by weight unless otherwise specified.

EXAMPLE 1 No Promoter A suitably sized autoclave was charged with 22.2 parts of dodecene-l, 24.3 parts of methanol, 1.4 parts of HzPtCl -fil-l O and 2.3 parts of SnCl -2H2O. Carbon monoxide was introduced into the autoclave to a pressure of 2,000 psi. The reaction mass was heated to C. with stirring. The carbon monoxide was then added to a total pressure of 3,000 psi. The reaction was continued at this temperature for 12 hours. During this time a total pressure drop of 500 p.s.i. was recorded. The reaction mass was cooled to room temperature and the autoclave was vented; 54 parts of liquid product was obtained. Analysis of the product by vapor phase chromatography showed that olefin conversion was 86 percent and the yield of methyl tridecanoate and methyl a-methyl dodecanoate based on this conversion was 98 percent.

With Promoter A suitable sized autoclave was charged with 14.7

parts of dodecene-l, 16.6 parts of methanol, 16.5 parts of acetone, 1.4 parts of H PtCl 'I-l and 2.3 parts of SnCl 2H 0. Carbon monoxide was introduced to a pressure of 2,000 p.s.i. The reaction mass was heated to 75 C. and CO was introduced to a total pressure of 3 ,000 p.s.i. The reaction was continued at this temperature for 5 hours, a pressure drop of 310 p.s.i. being recorded. The reaction mass was cooled to room temperature and the autoclave was vented; 64.5 parts of a liquid product was obtained. Analysis of this product by vapor phase chromatography showed that the conversion of olefin was 92 percent and the yield of methyl tridecanoate and methyl a-methyl dodecanoate based on the conversion was 96 percent.

EXAMPLE 3 No Promoter A suitably sized autoclave was'charged with 14.7 parts of dodecene-l, 15.9 parts of methanol, 1.4 parts of H PtCl -H 0 and 2.3 parts of the SnCl 2H 0. Carbon monoxide was introduced to a pressure of 2,000

p.s.i. The reaction mass was heated to 90 C. and car bon monoxide was added to a total pressure of 3,100 p.s.i. The reaction was continued for 1 hour. A pressure drop of 50 p.s.i. was recorded. The reaction mass was cooled to room temperature and the autoclave was vented; 33.8 parts of liquid product was obtained. Analysis of the product by vapor phase chromotography showed that olefin conversion was 50 percent, with the major product being methyl tridecanoate.

EXAMPLE 4 With Promoter A suitable sized autoclave was charged with 16.2 parts of dodecene-l, 14.4 parts of methanol, 24 parts of acetone, 1.4 parts of H PtCl '1-I 0 and 2.3 parts of SnCl -2H 0. Carbon monoxide was added to a pressure.

The improvement in-rate of reaction is clearly illustrated by the examples set out above. Example 3 shows that the reaction of dodecene-l with CO and methanol in the presence of the mixed tin/platinum catalyst at 90 C. resulted only 50 percent conversion of dodecene- 1 after 1 hour. By percent conversion, I mean that percent of the total charge which reacted with the CO and alcohol. In other words, only 50 percent of the dodecene-l reacted in 1 hour at 90 C. Using the same reactant and catalyst system of Example 3, but adding acetone as a promoter, the conversion of dodecene-l at 90 C. after 1 hour was increased to 88 percent (Example 4). Thus, the amount of product obtained using the promoter was increased by more than one-half. In Example l, dodecene-l, methanol and CO were reacted using a tin/platinum alcohol soluble catalyst. After 12 hours at C., the conversion of dodecene-l was 86 percent. In Example 2, by carrying out the reaction with the same reactants and the same conditions as in Example 1, but adding acetone as a promoter, the same olefin conversion was obtained after only 5 hours. Thus, again the reaction rate was sigiificantly increased as indicated by the substantially shorter reaction time required when using acetone as a promoter. Thus, using the promoter system of the present invention, the rate of carboxylation of olefins to produce esters is substantially increased.

The following examples illustrate the improved reaction rate effected by a promoter when a normally gaseous olefin reactant, namely propylene is used. All parts are by weight unless otherwise indicated.

Example 5 No Promoter A suitably sized autoclave was charged with 96 parts of methanol, 3.9 parts of H PtCl -I-I 0, 8.4 parts of SfiCl '2H 0. The autoclave was flushed twice with CO. Then, 31.6 parts of propylene was charged to the autoclave; and carbon monoxide was added to a pressure of 2,000 p.s.i. The reaction mixture was heated to C. and the pressure was adjusted with CO to 3,000 p.s.i. The reaction was continued at this temperature for 2 hours during which a pressure drop of 500 p.s.i. was observed. The reaction mass was then cooled to room temperature and the autoclave was vented. 135.2 parts of liquid product were obtained. Analysis of the product by vapor phase chromatography showed that conversion of olefin was 52 percent. The yield of methylbutyrates was 100 percent, of which 62 percent was the linear ester.

EXAMPLE 6 With Promoter A suitably sized autoclave was charged with 32 parts of methanol, about parts of acetone, 1.3 parts of H PtCl H Q), 2.8 parts of SnCl '2I-l 0. The autoclave was flushed twice with CO. Then 16 parts of propylene were charged to the autoclave; and carbon monoxide was added to a pressure of 2,000 p.s.i. The reaction mixture was heated to 90 C. and the pressure was ad justed with CO to 3,000 p.s.i. The reaction was continued at this temperature for 2 hours during which a pressure drop of 400 p.s.i. was observed. The reaction mass was then cooled to room temperature and the autoclave was vented. 174.3 parts of liquid product were obtained. Analysis of the product by vapor phase chromatography showed that conversion of olefin was 80 percent. The yield of methylbutyrates was 100 percent, of which 67 percent was the linear ester.

Thus, in Example 5 the conversion of propylene to methylbutyrates was 52 percent. In Example 6, under the same reaction conditions, but in the presence of acetone promoter, the conversion of propylene was increased to 80 percent. The addition of promoter, therefore, improved the conversion by almost 50 percent.

Following is a series of examples illustrating the process of the present invention.

EXAMPLE 7 A suitably sized autoclave was charged with 65 millimoles of 1,7-octadiene, 487 millimoles of methanol, 30 milliliters of acetone, 1.0 grams of H PtCl 'll-l tl, 2.3 grams of SnCl 2H 0, and 1.2 grams of H 0. The autoclave was flushed twice with CO. Then carbon monoxide was added to a pressure of 2,750 p.s.i. The reaction mixture was heated to 100 C. and the pressure was adjusted with CO to 3,175 p.s.i. The reaction was continued at this temperature for 1 hour during which a pressure drop of 525 p.s.i. was observed. The reaction mass was then cooled to room temperature and the autoclave was vented. 62 grams of liquid product were obtained. Analysis of the product by vapor phase chromatography showed that conversion of olefin was 100 percent; and it contained diesters of a clicarboxylic acid (40 percent yield of which 70 percent was linear diester) and monoesters of an unsaturated acid (7 percent yield of which 29 percent was linear ester).

Non-hydrated catalyst component combinations such as GeCl and H PtBr SnCL, and H PtCh; Gel, and l-l Ptl are similarly effective in the process of Example 7.

EXAMPLE 8 A suitably sized autoclave was charged with 90 millimoles of l-dodecene, 494 millimoles of methanol, 32 milliliters of acetone, 1.0 grams of H PtCl -H 0, 2.3 grams of SnC1 -2H 0, and 2.4 grams of H 0. The autoclave was flushed twice with CO. Then carbon monoxide was added to a pressure of 2,750 p.s.i. The reaction mixture was heated to 90 C. and the pressure was adjusted with CO to 3,140 p.s.i. The reaction was continued at this temperature for 1 hour during which a pressure drop of 300 p.s.i. was observed. The reaction mass was then cooled to room temperature and the autoclave was vented. 61.4 grams of liquid product were obtained. Analysis of the product by vapor phase chromatography showed that conversion of olefin was 36 percent; and the yield of methyltridecanoates was 100 percent, of which 83 percent was the linear ester.

EXAMPLE 9 A suitably sized autoclave was charged with 91 millimoles of l-dodecene, 482 millimoles of methanol, 30 milliliters of acetone, 1.0 grams of H PtCl 'l-l ll, 1.7

, grams of GeCl The autoclave was flushed twice with CO. Then, carbon monxoide was added to a pressure of 2,700 p.s.i. The reaction mixture was heated to 90 C. and the pressure was adjusted with CO to 3,140 p.s.i. The reaction was continued at this temperature for 24 hours during which a pressure drop of 1,180 p.s.i. was observed. The reaction mass was then cooler to room temperature and the autoclave was vented. 58 grams of liquid product were obtained Analysis of the product by vapor phase chromatography showed that conversion of olefin was 82 percent; and the yield of methyltridecanoates was 90 percent, of which 79 percent was the linear ester.

EXAMPLE 10 A suitably sized autoclave was charged with 157 millimoles of hexene-l, 488 millimoles of methanol, 30 milliliters of acetone, 1,4 grams of H PtC1 -H 0, 2.3

grams of SnCl '21-l 0. The autoclave was flushed twice with CO. Then, carbon monoxide was added to a pressure of 2,700 p.s.i. The reaction mixture was heated to 80 C. and the pressure was adjusted with CO to 3,000 p.s.i. The reaction was continued at this temperature for 1 hour during which a pressure drop of 400 p.s.i. was observed. The reaction mass was then cooled to room temperature and the autoclave was vented. 58.1 grams of liquid product were obtained. Analysis of the product by vapor phase chromatography showed that conversion of olefin was 100 percent; and the yield of methylheptanoates was 50 percent, of which 80 percent was the linear ester.

Similar results are obtained when H PtCl l-l ll and SnBr or H PtCl, and GeBr are used as the catalyst components.

EXAMPLE 11 A suitably sized autoclave was charged with 224 millimoles of l-dodecene, 50 milliliters of methanol, 75 milliliters of acetone, 1.0 grams of H PtCl 'l-l 0, 2.3

, grams of SnCl '2H 0. The autoclave was flushed twice with CO. Then, carbon monoxide was added to a pressure of 2,000 p.s.i. The reaction mixture was heated to C. and the pressure was adjusted with CO to 3,025 p.s.i. The reaction was continued at this temperature for 1 hour during which a pressure drop of p.s.i. was observed. The reaction mass was then cooled to room temperature and the autoclave was vented. 136.2 grams of liquid product were obtained. Analysis of the product by vapor phase chromatography showed that conversion of olefin was 50 percent; and the yield of methyltridecanoates was 87 percent, of which 83 percent was the linear ester.

Replacing l-dodecene with l-butene in Example 11 produces a comparable yield of methylpentanoates.

EXAMPLE 12 A suitable sized autoclave was charged with 228 millimoles of l-dodecene, 50 milliliters of methanol, 75 milliliters of acetone, 2.5 grams of H PtCl -H 0, 5.8 grams of SnCl '2l-l 0. The autoclave was flushed twice with CO. Then, carbon monoxide was added to a pressure of 2,000 p.s.i. The reaction mixture was heated to 90 C. and the pressure was adjusted with CO to 3,000 p.s.i. The reaction was continued at this temperature for 1 hour during which a pressure drop of p.s.i. was observed. The reaction mass was then cooled to room temperature and the autoclave was vented. 143.7 grams of liquid product were obtained. Analysis of the product by vapor phase chromatography showed that conversion of olefin was 75 percent; and the yield of methyltridecanoates was 91 percent, of which 84 percent was the linear ester.

Comparable yields of the ethyl, isopropyl, n-decyl and phenyl tridecanoates are obtained when ethanol, isopropanol, n-decanol and phenol respectively are used in place of methanol in Example 12.

EXAMPLE 13 A suitably sized autoclave was charged with 268 millimoles of l-dodecene, 1,000 millimoles of methanol, 50 milliliters of acetone, 2.6 grams of l'l PtCl 'l-l tl, 5 .6 grams of SnCl -2l-l 0. The autoclave was flushed twice with CO. Then, carbon monoxide was added to a presroom temperature and the autoclave was vented. sure of 2,500 p.s.i. The reaction mixture was heated to Analysis of the product obtained by vapor phase 90 C. and the pressure was adjusted with CO to 3,170 chromatography showed that conversion of olefin was p.s.i. The reaction was continued at this temperature 100 percent. The yield of methyltridecanoates was 64 for 1 hour. The reaction mass was then cooled to room percent, of which 84 percent was the linear ester; and

temperature and the autoclave was vented. the product also contained 34 percent internal Analysis of the product obtained by vapor phase dodecene isomers. chromatography showed that conversion of olefin was The following table contains data for another series 99 percent; the yield of methyltridecanoates was 76 of examples of the carboxylation process in which a percent, of which 80 percent was the linear ester. The promoter is used. in each case, where the analogous product also contained 24 percent internal dodecene reaction is run without a promoter, the rate of carboxisomers. ylation is significantly lower. The relationship of the Analogous results are obtained when the Example 13 two rates of reaction, that is, with a promoter vs. reaction is carried out at 50, 75, 115, 125 C. or 150 without a promoter, for this series of examples (as well C. as for Examples 7-15) is of the same general order as that illustrated by the Examples 1 and 2, Examples 3 EXAMPLE 14 and 4 and Examples 5 and 6. Conversion in the exam- A suitably sized autoclave was charged with 268 mil- P described herein is Calculated as fOHOWSI limoles of l-dodecene, 1,000 millimoles of methanol,

100 milliliters of acetone, 2.6 grams of H PtCl -H 0, 7 olel1n charged-olefinrecovered 5.6 grams of SnCl -21-l 0. The autoclave was flushed olefin charged TABLE 1 CO Reaction Catalyst pressure tempera- Olclm (moles) Alcohol (moles) (partszpurts) l (p.s.i.) ture 0.) Promoter (weight percent) 1 Major ester product 3 Douche-1 (l) Ethanol (l) GGCltIHzPtCh 1,500 80 Methyl ethyl ketone (50) Ethyl undecanoate.

:1) Ientadeeene-l (1)." Tcrt-butanol (2)... GDB1'4:H2P1.B1'4 6,000 85 Cyclohexanone Tert-butylhexadecanoatc.

0:1 Dotriacontent-l (l) n-Hexano1(1.5) GQClitHzPtIe 2, 500 90 Dilsoamyl ether (10) n-Hexyl-tritrlaeontanoate.

Hex)adecadiene 1,4 Isopropanol (10). GedlhH PtL 4, 500 75 Tetrahydroiuran (60) Isopropyl heptadecanoate.

1 :1 Nonadecene-l (1)... 2-ethy1-n-hexanol(8) SnClzlHaPtBIs 2,100 110 Methyl-tert-butyl ketone (70) 2-ethy1-n-hexyl elcosanoate.

:1. 1 Tetracosene-l (1)- n-Decanol (6.5) GeCllzHzPtClc 3,600 100 1,2-blsl2-(2-butoxy-ethoxy)- n-Decyl pentacosanoate.

.5: ethoxylethane (20). Heptadeeened (l) Cyclohexanol (4).. SnOlnHzPtBri 750 96 1,2-dimethoxy ethane (44)..." Cyclohexyl oetadecanoate.

:1. Octadiene-1,7 (1).... n-Butanol (3.5). SnBlztHzPtBls 3,000 120 B1s[2-(2ethoxycthoxy)- di-n-Butyl sebaeatc.

:0. cthyl]ether (56). Octadeeene-l (1).-.. 2-pentanol (9) SnSOrzHzPtIc 1,000 70 1,3-d1oxane (32) 1-metliyl-n-butylnonadecnnoatc.

Pentene-l (1) 4-nonanol (5) SnfigHzPtVl; 10,000 82 Dilsobutyl kotono (66) 1-n-pentyll1exanoate.

1 Weight ratio; also either or both catalyst components may be hydrated or non-hydrated. 2 Based on total reactant charge. 3 Branched isomers are also produced as illustrated by Equation I above.

twice with CO. Then, carbon monoxide was added to a The ester products of the present reaction have many gressuire (9)3 25430d pfisj. The reactio: miiaturtzl l gses indthe cheimical fieldlFor example, the esters gray t t o t .5 32301.81. T53 mJJ iZ JZ Z. m- Z5i n hZ3i3Zf;fi if? ifif lsifiiiiiiai imef perature for 1 hour. The reaction mass was then cooled mediates in ester interchange reactions. The esters may to Xwrln tempfertzliqture anjd the agitoclaijlegvas vented.h also be hydrolyzceid to yield acids which are useful as dena ysis o e pro uct o tame y vapor p ase tergent mterme ates. chromatography showed that conversion of olefin was The tin or germanium Salts d noble metal acids 100 percent. The yield of methyltridecanoates was 72 d as catalysts i h present invention are, i P 3 01 lr P g l} -dr d general, soluble in alcohol. Soluble in alcohol means lml 8r is are 0 tame W en ate soluble in a lower alkanol such as ethanol, methanol, chloroplatinic acid and stannous chloride are used in isopropanol d th lik Salt f th etals and Example Dii ylk L noble metal acids which are not soluble in alcohol but ioiiyethylgfethtert ll,2-diprolpsoxygthanui; d meta/21122 32; :ivlhiclgeare sgltgirllefliln thttke1 olelfin (and/or the promoter calm e one 6 e0 slm ar res W 611 6 In so use e 0 er an tin or germanium sa ts acetone in Example and either with the hydrated or and noble metal acids which are not soluble in any the non-hydrated y l component of the reaction system can also be used. In EXAMPLE 15 this case, the combination of tin or germanium salts A suitably sized autoclave was charged with 268 miland noble metal aqids y be dispersed directly in the limoles of l-dodecene, 1,000 millimoles of methanol, macho" System g methods known In the the 100 milliliters of acetone, 2.6 grams of H PtCl -H 0, metal Salts and noble metal aclds. may be used 5.6 grams of SnCl -2l-l 0. The autoclave was flushed deposlted Onanmen Supporttwice with CO. Then, carbon monoxide was added to a The process of this invention is properly described pressure of 1,000 p.s.i. The reaction mixture was above. The examples presented serve to illustrate, but heated to C. and the pressure was adjusted with C0 are not meant to limit this invented process. It is into 1,500 p.s.i. The reaction mass was then cooled to tended that this invention be limited only within the scope of the following claims.

i claim:

i. A process for preparing carboxylic acid esters which comprises reacting C C olefin, characterized by having A. at least one alpha carbon-to-carbon double bond,

and

B. a hydrogen on the 2-carbon atom of said a-double bond, with carbon monoxide and a (I -C alcohol reactant at an olefinzalcohol reactant ratio of lzl to 1:10 in the presence of a. from 0.0001 to 0.2 mole of contained platinum metal per mole of alcohol reactant, of a catalyst which is a combination of i. an alcohol soluble salt of a metal selected from tin and germanium, and ii. :1 haloplatinum acid wherein the molar ratio of said saltzsaid acid is from 1:1 to 20:1, and from l/o to about 70/o by weight, based on the total olefin/alcohol reactant, of b. a promoter selected from the class consisting of i. alkyl ketones having up to 11 carbon atoms and one ii. alkyl ethers having from four to about 16 can bon atoms and up to 6 0- groups, and iii. morpholine. 2. The process of claim 1 wherein said alcohol reactant is a (l -C alkanol.

3. The process of claim 2 wherein said alkanol is a C C monohydroxy primary alkanol.

4. The process of claim 3 wherein said alkanol is methanol.

5. The process of claim 1 wherein the molar ratio of olefinzaicohol reactant is from 1:1 to about 1:6.

6. The process of claim 5 wherein said olefimalcohol molar ratio is 1:2 to about 1:6.

7. The process of claim 1 wherein the reaction temperature is from about 50 C. to about 275 C. and the reaction pressure is from about 500 to about 10,000 pounds per square inch.

8. The process of claim 7 wherein said reaction temperature is from about 70 C. to about 120 C. and said reaction pressure is from about 750 to 5,000 pounds per square inch.

9. The process of claim 8 wherein said olefinzalcohol reactant ratio is 1:1 to about 1:6 and said alcohol reactant is a C -C alkanol.

10. The process of claim 9 wherein said alkanol is a C -C monohydroxy alkanol.

11. The process of claim 1 wherein said promoter is alkyl ketone.

12. The process of claim 1 wherein said promoter is alkyl ether.

13. The process of claim 1 wherein said aicohoi soluble salt is a halogen salt of tin or germanium.

14. The process of claim 13 wherein said alcohol soluble salt is a halogen of tin.

15. The process of claim 13 wherein said haloplatinum acid is haloplatinic acid.

16. The process of claim 14 wherein said haloplatinum acid is chloroplatinic acid.

17. Tee process of claim 1 wherein said olefin is a monoolefin.

18. The process of claim 57 wherein said aicohol reactant is a C -C alkanol.

19. The process of claim 10 wherein said promoter is alkyl ketone.

20. The process of claim 19 wherein said alkanol is a C -C monohydroxy alkanol.

21. The process of claim 20 wherein said alkanol is methanol.

22. The process of claim 19 wherein said promoter is acetone.

23. The process of claim 13 wherein said promoter is an alkyl ether.

24. The process of claim 23 wherein said alkyl ether is 1,2-dirnethoxy ethane.

25. The process of claim 8 wherein said olefin is C -C olefin, said alcohol reactant is C C monohydroxy alkanol, said olefimalcohol reactant molar ratio is 1:1 to about 1:6, and said alcohol soluble salt is a halide of germanium or tin.

26. The process of claim 25 wherein said olefin is an a-monooiefin.

27. The process of claim 25 wherein said promoter is alkyl ketone.

28. The process of claim 25 wherein said promoter is alkyl ether.

29. The process of claim 25 wherein said alkanol is a C,-C alkanol.

30. The process of claim 29 wherein said alkanol is methanol.

31. The process of claim 30 wherein said promoter is acetone.

32. The process of claim 31 wherein said olefin is propylene.

33. The process of claim 31 wherein said olefin is dodecene. 

2. The process of claim 1 wherein said alcohol reactant is a C1-C10 alkanol.
 3. The process of claim 2 wherein said alkanol is a C1-C5 monohydroxy primary alkanol.
 4. The process of claim 3 wherein said alkanol is methanol.
 5. The process of claim 1 wherein the molar ratio of olefin: alcohol reactant is from 1:1 to about 1:6.
 6. The process of claim 5 wherein said olefin:alcohol molar ratio is 1:2 to about 1:6.
 7. The process of claim 1 wherein the reaction temperature is from about 50* C. to about 275* C. and the reaction pressure is from about 500 to about 10,000 pounds per square inch.
 8. The process of claim 7 wherein said reaction temperature is from about 70* C. to about 120* C. and said reaction pressure is from about 750 to 5,000 pounds per square inch.
 9. The process of claim 8 wherein said olefin:alcohol reactant ratio is 1:1 to about 1:6 and said alcohol reactant is a C1-C10 alkanol.
 10. The process of claim 9 wherein said alkanol is a C1-C5 monohydroxy alkanol.
 11. The process of claim 1 wherein said promoter is alkyl ketone.
 12. The process of claim 1 wherein said promoter is alkyl ether.
 13. The process of claim 1 wherein said alcohol soluble salt is a halogen salt of tin or germanium.
 14. The process of claim 13 wherein said alcohol soluble salt is a halogen of tin.
 15. The process of claim 13 wherein said haloplatinum acid is haloplatinic acid.
 16. The process of claim 14 wherein said haloplatinum acid is chloroplatinic acid.
 17. Tee process of claim 1 wherein said olefin is a monoolefin.
 18. The process of claim 17 wherein said alcohol reactant is a C1-C10 alkanol.
 19. The process of claim 18 wherein said promoter is alkyl ketone.
 20. The process of claim 19 wherein said alkanol is a C1-C5 monohydroxy alkanol.
 21. The process of claim 20 wherein said alkanol is methanol.
 22. The process of claim 19 wherein said promoter is acetone.
 23. The process of claim 18 wherein said promoter is an alkyl ether.
 24. The process of claim 23 wherein said alkyl ether is 1,2-dimethoxy ethane.
 25. The process of claim 8 wherein said olefin is C8-C24 olefin, said alcohol reactant is C1-C10 monohydroxy alkanol, said olefin: alcohol reactant molar ratio is 1:1 to about 1:6, and said alcohol soluble salt is a halide of germanium or tin.
 26. The process of claim 25 wherein said olefin is an Alpha -monoolefin.
 27. The process of claim 25 wherein said promoter is alkyl ketone.
 28. The process of claim 25 wherein said promoter is alkyl ether.
 29. The process of claim 25 wherein said alkanol is a C1-C5 alkanol.
 30. The process of claim 29 wherein said alkanol is methanol.
 31. The process of claim 30 wherein said promoter is acetone.
 32. The process of claim 31 wherein said olefin is propylene.
 33. The process of claim 31 wherein said olefin is dodecene. 